(a) If you have no preliminary estimate for p, how many medical files should you include in a random sample in order to be 85% sure that the point estimate p will be within a distance of 0.03 from p? Find the critical value for 85% confidence level, z0.85, and find the specified maximal error of estimate, E. (Round your answers to two decimal places.) Compute the sample size n for estimating the proportion p of all people who have blood type B under these restrictions. (Round your answer up to the nearest whole number.) medical files (b) Answer part (a) if you use the preliminary estimate that about 8 out of 90 people have blood type B. (Round your proportions to three decimal places and your sample size up to the nearest whole number.) 1-p = medical files